1. Field of the Invention
The present relates to dental chairs and wheelchairs and more particularly, to a converter which converts a wheelchair to a dental chair.
2. Description of the Prior Art
There are presently attachments for wheelchairs which convert them to walkers and which hold trays on which the occupants may eat. These attachments generally are formed of similar materials as the wheelchairs. U.S. Pat. No. 3,708,182, entitled Combination Wheel Chair and Walker, issued to Henry Markiel on Jan. 2, 1973, teaches a walker and wheel chair combination in which the walker is made up of a single wheel supported by a U-shaped frame which is attached to the front legs of a wheel chair. Thus a person sitting in the wheel chair can rise to his feet, support himself on the walker and walk.
The wheel chairs themselves are also being improved as in U.S. Pat. No. 3,881,773, entitled Reclining Back Wheelchair, issued to Keith S. Rodaway on Mar. 6, 1975 which provides in combination with a frame structure supporting a seat, a reclining back assembly that includes a back rest pivoted at a point to the frame structure for movement from an upright position to a reclining position, an adjusting tube pivoted at one end at a second pivot point to the back rest, a guide for slideably engaging the other end of the adjusting tube and pivoted at a third pivot point to the frame structure, actuating linkage and a pawl member coupled to the actuating linkage, and in conjunction with which supports the back rest.
U.S. Pat. No. 3,790,212, entitled Foot Support for Wheelchairs, issued to Shigemitsu Suyetani on Feb. 5, 1974, teaches a leg rest arrangement for wheelchairs of the type in which a foot rest is pivotally mounted on a supporting member and moveable from a foot rest position to a closed position. There is provided a leg support spaced vertically from the foot rest for supporting the back of the leg of the user when the foot is resting on the foot rest. The support is operatively connected with the foot rest so that when the foot rest is pivoted to the closed position the leg support is also pivoted to the closed position and is compactly and closely adjacent to the foot rest in the closed position.
There have been improvements to dental chairs during recent years. U.S. Pat. No. 3,948,559, entitled Adjustable Chair, issued to Barry A. Hain and Ronald C. Webb on Apr. 6, 1976, teaches an adjustable chair in combination a base having an upper portion movable vertically relative to the lower portion thereof, a seat unit supported upon the upper portion for direct vertical movement therewith. U.S. Pat. No. 3,968,990, entitled Dental Patient's Chair Including Padded Backrest, issued to Erich Heubeck on July 13, 1976 teaches a dental patient's chair wherein a padding-supporting portion includes a rigid carrier or support frame having fastened to the side remote from the padding cover a unitary shaped element covering the rearwardly facing surface of the backrest, and which is exteriorly provided with a washable surface.
Other improvements to dental chairs in recent years include include those taught in U.S. Pat. No. 3,934,928, U.S. Pat. No. 3,934,929 and U.S. Pat. No. 3,934,931. U.S. Pat. No. 3,934,928, entitled Adjustable Operatory Chair, issued to Phillip C. Johson on Jan. 27, 1976, teaches a device for positioning the backrest of an operatory chair. U.S. Pat. No. 3,934,929, entitled Adjustable Dental Chair, issued to Azriel Jay Rabinowitz on Jan. 27, 1976, teaches articulation of the backrest, seat and footrest which is accomplished by a single motor. U.S. Pat. No. 3,934,931, entitled Dental Chair, issued to Takahiro Matsui and Osamu Uwamori on Jan. 27, 1976, teaches a dental chair with a back attached to the seat so as to be inclinable relative to the seat. All of the above cited patents are concerned with providing comfort to both the dentist and his patients. None of these patents describe a wheel chair converter which can convert a wheel chair to a dental chair so that a patient confined to a wheel chair can receive not only dental treatment comfortably, but also efficiently, because the dentist will be operating in a somewhat similar manner on this patient as he does for his other patients.
The need for a wheel chair converter that provides control, movement, and mobility of the patient for the dentist exists because the patient's head must be stabilized so that a proper examination, diagnosis and definitive treatment may be instituted by the dentist.